Best way to make sure your slideout extends smoothly

If you are talking about the seals they are accessed from the inside with the slide partly retracted and talcum powder works great. Baby powder is just talcum powder with a scent added. If you are talking about the wipers on the outside then silicone or 303 works well. Many people confuse the seals which seal out air and water with the wipers which clean the slide when it retracts.